On Sun, Feb 6, 2011 at 11:15 PM, Mathieu Bouchard matju@artengine.ca wrote:
On Sun, 6 Feb 2011, Spencer Russell wrote:
[1] gives the magnitude frequency response given the biquad coefficents, and it linked to from several places around the net. Is this the sort of thing you're looking for? [1] http://bit.ly/eFck4j
This link got me directly to :
USB complete: everything you need to develop custom USB peripherals Par Jan Axelson Chapitre 12 Page 364
and nothing else. (??)
Whoops, I meant to send this: http://bit.ly/gUCBu4. Sorry.
Here he's basically just taken the transfer function of a biquad and made the z = exp(j*w/Fs) as Mike suggested, followed by taking the magnitude and log-scaling for dB, but he's done the algebraic legwork. Just note that w (lower-case omega) is 2*pi*f and you should be good to go. He's also done some trig-substitution for more numerical precision.
-s